Back to matchesWe found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleLetter to the editor.AuthorsDyrholm, Mads; Parra, Lucas CPublicationBiostatistics, 2013, Vol 14, Issue 2, p405ISSN1465-4644Publication typeJournal ArticleDOIbiostatistics/kxs039